Orthopaedics Flashcards
Give 5 red flags for lower back pain
Red flags for lower back pain
age < 20 years or > 50 years
history of previous malignancy
night pain
history of trauma
systemically unwell e.g. weight loss, fever
What investigations are indicated for non-specific lower back pain
Investigation
-lumbar spine x-ray should not be offered
MRI
-should only be offered to patients with non-specific back pain ‘only if the result is likely to change management’ and to patients where malignancy, infection, fracture, cauda equina or ankylosing spondylitis is suspected
it is the most useful imaging modality as no other imaging can see neurological / soft tissue structures
What advice should you give people with non-specific lower back pain?what analgesia is indicated?
Advice to people with low back pain
try to encourage self-management
stay physically active and exercise
Analgesia
-NSAIDS are now recommended first-line for patients with back pain. This follows studies that show paracetamol monotherapy is relatively ineffective for back pain
-proton pump inhibitors should be co-prescribed for patients over the age of 45 years who are given NSAIDs
-NICE guidelines on neuropathic pain should be followed for patients with sciatica
Give four treatments for non-specific lower back pain other than analgesia?
Other possible treatments
-exercise programme: ‘Consider a group exercise programme (biomechanical, aerobic, mindbody or a combination of approaches) within the NHS for people ‘
-manual therapy (spinal manipulation, -mobilisation or soft tissue techniques such as massage) ‘but only as part of a treatment package including exercise, with or without psychological therapy.’
-radiofrequency denervation
-epidural injections of local anaesthetic and steroid for acute and severe sciatica
In sciatica what are the features if the L3 nerve root is compressed?
Sensory loss over anterior thigh
Weak hip flexion, knee extension and hip adduction
Reduced knee reflex
Positive femoral stretch test
In sciatica what are the features if the L4 nerve root is compressed?
-Sensory loss anterior aspect of knee and medial malleolus
-Weak knee extension and hip adduction
-Reduced knee reflex
-Positive femoral stretch test
In sciatica what are the features if the L5 nerve root is compressed?
Sensory loss dorsum of foot
Weakness in foot and big toe dorsiflexion
Reflexes intact
Positive sciatic nerve stretch test
In sciatica what are the features if the S1 nerve root is compressed?
-Sensory loss posterolateral aspect of leg and lateral aspect of foot
-Weakness in plantar flexion of foot
-Reduced ankle reflex
-Positive sciatic nerve stretch test
What is the management of sciatica?
Management
similar to that of other musculoskeletal lower back pain: analgesia, physiotherapy, exercises
NICE recommend using the same drugs as for back pain without sciatica symptoms i.e. first-line is NSAIDs +/- proton pump inhibitors rather than using neuropathic analgesia (e.g. duloxetine)
if symptoms persist e.g. after 4-6 weeks) then referral for consideration of MRI is appropriate
Describe clinical features for lower back pain due to facet joint issues?
-May be acute or chronic
-Pain worse in the morning and on standing
-On examination there may be pain over the facets. The pain is typically worse on extension of the back
Describe clinical features of lower back pain due to spinal stenosis? 5
-Usually gradual onset
-Unilateral or bilateral leg pain (with or without back pain), numbness, and weakness which is worse on walking. Resolves when sits down. Pain may be described as ‘aching’, ‘crawling’.
-Relieved by sitting down, leaning forwards and crouching down
-Clinical examination is often normal
-Requires MRI to confirm diagnosis
What is lumbar spinal stenosis? how can this be differentiated from claudication?
Lumbar spinal stenosis is a condition in which the central canal is narrowed by tumour, disk prolapse or other similar degenerative changes.
Patients may present with a combination of back pain, neuropathic pain and symptoms mimicking claudication. One of the main features that may help to differentiate it from true claudication in the history is the positional element to the pain. Sitting is better than standing and patients may find it easier to walk uphill rather than downhill. The neurogenic claudication type history makes lumbar spinal stenosis a likely underlying diagnosis, the absence of such symptoms makes it far less likely.
Describe the pathophysiology of lumbar spinal stenosis?
Degenerative disease is the commonest underlying cause. Degeneration is believed to begin in the intervertebral disk where biochemical changes such as cell death and loss of proteoglycan and water content lead to progressive disk bulging and collapse. This process leads to an increased stress transfer to the posterior facet joints, which accelerates cartilaginous degeneration, hypertrophy, and osteophyte formation; this is associated with thickening and distortion of the ligamentum flavum. The combination of the ventral disk bulging, osteophyte formation at the dorsal facet, and ligamentum flavum hyptertrophy combine to circumferentially narrow the spinal canal and the space available for the neural elements. The compression of the nerve roots of the cauda equina leads to the characteristic clinical signs and symptoms of lumbar spinal stenosis.
What is the investigation and management of lumbar spinal stenosis?
MRI scanning is the best modality for demonstrating the canal narrowing. Historically a bicycle test was used as true vascular claudicants could not complete the test.
Laminectomy
what is cauda equina syndrome? give 5 causes
Cauda equina syndrome (CES) is a rare but serious condition in which the lumbosacral nerve roots that extend below the spinal cord are compressed. It is important to consider CES in any patient who presents with new/worsening lower back pain. Late diagnosis may lead to permanent nerve damage resulting in long term leg weakness and urinary/bowel incontinence.
Causes
-the most common cause is a central disc prolapse
this typically occurs at L4/5 or L5/S1
other causes include:
-tumours: primary or metastatic
-infection: abscess, discitis
-trauma
-haematoma
Give some features of cauda equina syndrome: 5
It is important to recognise that CES may present in a variety of ways and there is no one symptom/sign that can diagnose nor exclude CES. Possible features include
-low back pain
-bilateral sciatica
-present in around 50% of cases
-reduced sensation/pins-and-needles in the perianal area
decreased anal tone
it is good practice to check anal tone in patients with new-onset back pain
however, studies show this has poor sensitivity and specificity for CES
urinary dysfunction
e.g. incontinence, reduced awareness of bladder filling, loss of urge to void
-incontinence is a late sign that may indicate irreversible damage
What is the investigation and management of cauda equina syndrome?
Investigation
urgent MRI
Management
surgical decompression
Give clinical features of lower back pain seen in ankylosing spondylitis 3
Typically a young man who presents with lower back pain and stiffness
Stiffness is usually worse in morning and improves with activity
Peripheral arthritis (25%, more common if female)
Give clinical features of lower back pain seen in peripheral arterial disease
-Pain on walking, relieved by rest
-Absent or weak foot pulses and other signs of limb ischaemia
-Past history may include smoking and other vascular diseases
Femoral nerve: L2-L4
-Give the motor innervation
-Give the sensory innervation
-What is the common mechanism of injury?
Femoral nerve
-Knee extension, thigh flexion
-Anterior and medial aspect of the thigh and lower leg
-Hip and pelvic fractures
-Stab/gunshot wounds
Obturator nerve L2-L4
-Give the motor innervation
-Give the sensory innervation
-What is the common mechanism of injury?
Thigh adduction
Medial thigh
Anterior hip dislocation
Lateral cutaneous nerve of thigh
-Give the motor innervation
-Give the sensory innervation
-What is the common mechanism of injury?
None
Lateral and posterior surfaces of the thigh
Compression of the nerve near the ASIS → meralgia paraesthetica, a condition characterised by pain, tingling and numbness in the distribution of the lateral cutaneous nerve
What is meralgia pareasthetica?
Meralgia paraesthetica comes from the Greek words meros for thigh and algos for pain and is often described as a syndrome of paraesthesia or anaesthesia in the distribution of the lateral femoral cutaneous nerve (LFCN). It is an entrapment mononeuropathy of the LFCN, but can also be iatrogenic after a surgical procedure, or result from a neuroma. Although uncommon, meralgia paraesthetica is not rare and is hence probably underdiagnosed.
Give the pathophysiology of meralgia paraesthetica?
Anatomy
-The LFCN is primarily a sensory nerve, carrying no motor fibres.
-It most commonly originates from the L2/3 segments.
-After passing behind the psoas muscle, it runs beneath the iliac fascia as it crosses the surface of the iliac muscle and eventually exits through or under the lateral aspect of the inguinal ligament.
-As the nerve curves medially and inferiorly around the anterior superior iliac spine (ASIS), it may be subject to repetitive trauma or pressure.
-Compression of this nerve anywhere along its course can lead to the development of meralgia paraesthetica.